Astros rookie Brandon Barnes heads back to the dugout after striking out during the fourth inning. Barnes got his first career hit and scored his first run in the ninth inning. (Karen Warren / Houston Chronicle)

Nationals left fielder Stephen Lombardozzi (1) looks through the legs of umpire Chris Conroy after tagging Justin Maxwell (44) out at second on a on a ground ball hit by J.D. Martinez (14) during the first inning. (Karen Warren / Houston Chronicle) less

Nationals left fielder Stephen Lombardozzi (1) looks through the legs of umpire Chris Conroy after tagging Justin Maxwell (44) out at second on a on a ground ball hit by J.D. Martinez (14) during the first ... more

Nationals starting pitcher Gio Gonzalez (47) reacts after a balk was called on him after he pitched to Carlos Corporan, advancing J.D. Martinez to second base during the fourth inning. (Karen Warren / Houston Chronicle) less

Nationals starting pitcher Gio Gonzalez (47) reacts after a balk was called on him after he pitched to Carlos Corporan, advancing J.D. Martinez to second base during the fourth inning. (Karen Warren / Houston ... more